A wireless communication system that wirelessly communicates between a wireless base station and another wireless base station without using a communication cable is known. An opposite antenna having directionality is used for this communication. To perform communication using a directional antenna, it is important that the antenna is always oriented in an appropriate direction to maximize the reception level. However, even when the antenna is set up in an appropriate direction, there are various factors to cause a change in the direction of the antenna by environmental effects after the installation, such as the deformation of an antenna installation base due to high winds or sunshine, earthquake shock or the like, for example.
Patent Literature 1 (Japanese Unexamined Patent Application Publication No. 2007-129624) discloses the antenna that detects a wind direction and a wind speed and controls the direction. The antenna disclosed in Patent Literature 1 includes a wind direction and speed calculation unit that measures a wind direction and a wind speed and a displacement estimation unit that, after the calculation, estimates an antenna orientation error due to the displacement of the antenna. The antenna is then driven toward a target direction so as to correct the error based on the calculation result. Thus, even when the antenna is displaced due to wind, it is possible to correct the orientation of the antenna to an appropriate direction.